1. Field of the Invention
This invention relates to thrust washers and to seals and in particular to an improved thrust washer and also to a unitary combination of said improved thrust washer and a seal.
2. Description of the Prior Art
In many applications, seals are used in proximity to thrust washers which can be, for example, a ring made of treated nylon material. These parts are purchased separately and installed separately. In addition, some applications require the four separate parts of: (1) a metal, seal-retaining ring, (2) a primary seal, (3) a thrust washer, and (4) a secondary seal, which separate parts must be purchased separately and installed separately.
It is an object of the present invention to overcome such problems in the prior art and to provide a unitary seal and thrust washer.
In prior art applications requiring thrust washers and which are not under load at all times, the prior art thrust washers have a tendency to "pound out" (plastics have a tendency to "plastic flow" which means, for example, that if a plastic thrust washer is hit enough times with no give, it has a tendency to deform and change its shape or extrude slightly).
It is another object of the present invention to overcome such problems in the prior art by providing a resiliently backed thrust washer and to also prevent shock build-up between two axially movable members. It is another object of the present invention to provide a rubber-backed thrust washer having an integral sealing lip.